Elusys Therapeutics is actively developing a novel, ultra high-affinity monoclonal antibody (Mab) to neutralize the lethal effects of anthrax toxin. Elusys's Mab, ETI-204, is directed against Protective Antigen (PA) of B. anthracis and is being developed for both prophylactic and therapeutic treatment of anthrax infections resulting from a bioterrorist attack. Anthrax is currently considered by the federal government to be the number one biowarfare threat. In both mouse and rabbit studies, ETI-204 has protected 100% of treated animals from death following exposure to anthrax toxin or inhaled spores. As a result of this compelling data, the Company is rapidly pursuing a well defined clinical development program with input from meetings with both the Office of Counterterrorism (OCTAP) and the FDA. This application is for funding to complete the final animal efficacy testing, human safety testing and pharmaceutical manufacturing necessary to apply for FDA approval of ETI-204 for treatment of anthrax infection in both pre- and post exposure situations. The specific aims of this application are: (1) to develop a scaleable ETI-204 manufacturing process; (2) to complete definitive efficacy testing in a primate spore challenge model: (3) to produce clinical-grade ETI- 204; and (4) to complete human safety trials. Due to the urgent national need for an effective anthrax therapeutic, Elusys, with funding from DoD, has already initiated and will have completed several additional animal efficacy and PK studies to further ensure the success of ETI-204's continued development as outlined in this application. Funding provided under this application would greatly facilitate and expedite the final development work necessary to validate the safety and efficacy of a much needed anthrax antidote to protect both military and civilian personnel.